Chemical vapor deposition methods are employed to form films of material on substrates such as wafers or other surfaces during the manufacture or processing of semiconductors. In chemical vapor deposition, a chemical vapor deposition precursor, also known as a chemical vapor deposition organometallic compound, is decomposed thermally, chemically, photochemically or by plasma activation, to form a thin film having a desired composition. For instance, a chemical vapor deposition organometallic precursor can be contacted with a substrate that is heated to a temperature higher than the decomposition temperature of the precursor, to form a metal or metal oxide film on the substrate.
Preferably, chemical vapor deposition organometallic precursors are volatile, heat decomposable and capable of producing uniform films under chemical vapor deposition conditions. In producing thin films by chemical vapor deposition processes, precursors that are liquid at room temperature, rather than solids, often are preferred.
The synthetic process utilized to generate the desired organometallic precursors is highly important, and must insure high purity, thoughput, and consistency. However, the air-sensitive nature of the starting materials and the final product make the synthesis of organometallic precursors more challenging. When starting materials are solids, it makes air-free transfer more difficult. Simply storing the starting materials can be problematic, and purity levels from commercial sources are rarely greater than 95% (which creates potential loses in yield and final product purity). Furthermore, filtering of the reaction must be performed in an inert atmosphere which presents another challenge. Therefore, developing a methodology for producing organometallic precursors that addresses the aforementioned potential hold-ups would be beneficial toward establishing the large scale production of these materials for use in the electronics industry.
Further, in developing methods for forming thin films by chemical vapor deposition methods, a need continues to exist for chemical vapor deposition organometallic precursors that preferably are liquid at room temperature, have relatively high vapor pressure and can form uniform films. A need continues to exist for developing new compounds and for exploring their potential as chemical vapor deposition precursors for film depositions. It would therefore be desirable in the art to provide a chemical vapor deposition precursor in liquid form and producable on a large scale with high yields. Further, it would be a significant advancement in the art to synthesize organometallic compounds on a commercial scale using a one step process where all manipulations are carried out in a single vessel, and which the route to the organometallic compounds does not require the isolation of an intermediate complex.